Former GB and KC scout provides an interesting tidbit on scouting and coaches/GMs:

Marc Lillibridge: When I look at it as a scout, it started with a medical and that's what you're really hoping to find out. When you're writing your report and you say you love a player, if you're a good scout, you know what range he's in. If you know he's a 4.5 guy and he does better than that, it should solidify it. If a guy is a 4.6, you can tell it on film. As a scout, you're there to reconfirm, but also it helps when you're in meetings with coaches. The coaches haven't seen those players because they're worried about keeping their job or getting a new job. Then the GM's, up until December, haven't watched a lot of film – unless you're Ted Thompson.

It's more to confirm the grade you have. Then there are teams like the Atlanta Falcons, for example, that have their board set before the Combine. They may make some tweaks here or there, but they believe in their scouts. The teams that draft well trust their scouts and believe in their judgment. The Combine is just there to solidify or kill a guy if you don't think he's good. For us, when I was scouting, it didn't change much. It confirmed things and gave us hard numbers. If it makes or breaks your draft as a scout, you're probably not going to be in the business for very long or with that team.